Neuromuscular blocking agents are employed in therapy as coadjuvants in surgical anaesthesia to obtain relaxation of skeletal muscles. Typically, therapy is performed by i.v. administration of a suitable dosage form. This dosage form may be administered by dissolving a freeze-dried powder, containing the active ingredient associated with some excipients, in water or another suitable solvent.
One neuromuscular blocking agent, vecuronium bromide, was first described in U.S. Pat. No. 3,553, 212 to Hewett et al. Various formulations for neuromuscular blocking agents, including vecuronium bromide, have also been proposed.
Several processes have been proposed for the preparation of neuromuscular blocking agents. According to the method described in U.S. Pat. No. 3,553,212, neuromuscular blocking agents may be prepared by synthons obtained by reacting a 16.alpha., 17.alpha.-oxido, or a 17.beta.-hydroxy-16-keto androstane with an amine at elevated temperature and pressure.
U.S. Pat. Nos. 4,101,545, 4,110,326, and 4,117,190 all to Tuba et al. propose a process for preparing diamino androstanes which includes reacting a diepoxy androstane with a cyclic amine, followed by reduction to the 17.beta.-hydroxy androstane.
There remains a need in the art for a new process of preparing diamino-androstane neuromuscular blocking agents.